Come the end of this year, someone other than Bill Horn will represent North County on the Board of Supervisors.

Termed out after 23 years of representing District 5, an area that spans nearly 1,800 square miles from the Pacific Ocean to Imperial County, Horn’s departure — along with that of Supervisor Ron Roberts — could herald the beginning of a wholesale change in the makeup of the board by 2020.

Vying to replace him are four candidates. Political strategists and observers uniformly believe the eventual winner will be San Marcos Mayor Jim Desmond, who has been endorsed by Horn, the Republican party, and the Deputy Sheriff’s Association. The political demographics of District 5 lean heavily toward the right.

Some say it is possible that Desmond may win the seat outright in the June 5 primary by gathering more than 50 percent of the vote.

Also running are longtime Oceanside City Councilman Jerry Kern; Jacqueline Arsivaud, a member of the San Dieguito Planning Group and chairwoman of the Elfin Forest/Harmony Grove Town Council; and Michelle Gomez, a legislative analyst and longtime volunteer.

District 5 represents a diverse population that includes the cities of Carlsbad, Oceanside and Camp Pendelton on the coast and runs all the way to Borrego Springs to the east. It includes Rancho Santa Fe, Fairbanks Ranch, 4S Ranch, San Marcos, Vista, Valley Center, Bonsall, Fallbrook, Rainbow, De Luz, Pauma Valley, Warner Springs, and Ranchita.

Desmond, 62, has been the mayor of San Marcos for 12 years and says he has learned a lot about government and government policies in that time.

“I’ve been able to make a lot of relationships in San Diego County and to get some things done and I’m running because I’m pretty much a basic government service kind of guy,” he told the Union-Tribune’s editorial board.

Desmond says he has the most experience of all the candidates as a leader of a city.

“I want to make sure the county remains fiscally responsible,” he said. “I want to make sure our residents stay safe. And I want to increase and enhance our infrastructure.”

Kern has been on the Oceanside City Council for 12 years and is generally considered to be Desmond’s biggest challenger.

“I feel I am the most qualified, coming from a full-service city on the coast,” Kern said. “I’ve dealt with Coastal Commission issues. We have an airport. We have a harbor. We have our own water department and police department. A lot of things the county deals with I’ve dealt with. I can hit the ground running.”

Kern said the housing crisis is real and he would likely support some of the big housing projects being proposed in North County along the Interstate 15 corridor.

“I think I can be of service,” he said. “I’ve always been in service to the people of Oceanside.”

The focus of Arsivaud’s campaign is what she feels is the negative influence that developers and the building industry have on the county and the excessive influence developers have with the current Board of Supervisors.

“I believe, and so do the people who support me, that we are heading to a future that will look more like Los Angeles than San Diego,” she told the editorial board.

“We have to think about smart growth versus sprawl. We have to think about technology solutions to traffic.”

Arsivaud is endorsed by a number of environmental groups and leaders and is involved in the signature-gathering campaign for the Save Our San Diego Countryside initiative. The initiative, if enough signatures are gathered by the end of this month, will ask voters to approve new regulations that would require county-wide votes for most amendments to the General Plan that seek to drastically increase the number of units that could be built under current zoning in the unincorporated parts of the county.

Gomez , 47, said she’s running for supervisor because she wants to make a difference for working families.

“I believe our current supervisors are sitting on a stockpile of money and reserves,” she told the editorial board. “And that is not benefiting our communities. It’s not benefiting our working families.”

She also said she’s running because something must be done about affordable housing and the homelessness crisis.

“We need to be making sure that we’re building in smart growth areas, near infrastructure, near transportation corridors,” she said. “We need to make sure we’re preserving our pristine open space, but at the same time building and developing affordable housing units. … Part of that is incentivizing developers to ensure that every time they build a project that they put some affordable housing units into that project.”

Reflecting his front-runner status, campaign financial filings show Desmond has far more cash on hand to spend on the election.

This year, Desmond has received more than $73,000 in campaign donations, which have been added to a beginning cash balance of $193,000. As of the most recent reporting period, which ended late last month, he has spent about $55,000 on the campaign and has about $220,000 in his campaign coffers.

Kern,meanwhile, has a cash balance of about $85,000, having raised $17,100 this year to add to a beginning balance of more than $111,000. He so far has spent about $43,000.

Arsivaud has received nearly $27,000 in campaign contributions, including a $5,000 loan from herself to the campaign. She has spent about $19,000, has $10,000 in debts, and has an $18,000 cash balance.

Gomez has received just over $5,000 in contributions of which she has spent about $500.

HERE’S A SNAPSHOT OF EACH CANDIDATE:

Jim Desmond

AGE: 62

A resident of San Marcos, Desmond has been mayor of that city for the past 12 years. He is employed as a captain for Delta Air Lines and has been married for 32 years to his wife Kerri. They have two grown children.

Endorsed by among others: Supervisor Bill Horn, the Deputy Sheriff’s Association and the local Republican Party.

QUOTE: “I think the difference between myself and my main (opponent), which is Mr. Kern from Oceanside, I’ve been the mayor of a city. I’ve been the leader of a city.”

Jacqueline Arsivaud

AGE: 59

A native of France, Arsivaud has lived in District 5 for more than a quarter-of-a-century. A resident of Elfin Forest since 1991, she has been married for 30 years to Alan Benjamin and has two grown children. Arsivaud is a member of the San Dieguito Planning Group and chairwoman of the Elfin Forest/Harmony Grove Town Council.

She is endorsed by former Supervisor Pam Slater-Price and many environmental groups and leaders.

QUOTE: “We need to elect people to the board who are committed to preserving San Diegans quality of life and that starts with limiting urban sprawl, which I see as an existential threat for us as a county.”

Jerry Kern

AGE: 65

Kern has been a member of the Oceanside City Council for 12 years and has been a resident, with his wife Blake, of that city for more than 40 years. The couple has two grown children.

Kern has been endorsed by, among others: State Sen. Pat Bates and Assemblymen Rocky Chavez and Randy Voepel.

QUOTE: “I think I’m well a qualified for the job. I think I can be of service. I’ve always been in service to the people of Oceanside. My basic philosophy of government is we’re in the service delivery business.”

Michelle Gomez

AGE: 47

Gomez is an Oceanside resident who works as a governmental affairs legislative analyst.

She is married to a Marine Corps veteran, Don, and endorsed by the Democratic Party, numerous labor unions and groups and the Sierra Club.

QUOTE: “I am running because I think we need a fresh face and a fresh perspective. I think our current county Board of Supervisors has been there too long. And I think that they are just going through the motions rather than affecting real change.”